State-of-the-art design of integrated circuits (micro chips) includes specifying the functionality of the chip in a standard hardware programming language such as Verilog (a hardware description language used to design and document electronic systems), synthesizing/mapping the circuit description into basic gates of a standard cell library using computer-aided design (CAD) tools such as Synopsys' DesignCompiler, produced by Synopsys, Inc. of Mountain View, Calif., placing and routing the gate netlist using CAD tools such as Magma's BlastFusion, produced by Magma, Inc. of San Jose, Calif., and finally verifying proper connectivity (LVS) and functionality of the circuit.
While all of these steps are important for the final quality of the integrated circuit, for most of these steps the achievable quality of implementation is design dependent. For example, a good Verilog code specifying circuit A does not make an independent circuit B any better. However, an efficient standard cell library—i.e., a group of cells used in forming circuits—makes all designs better. In other words, the quality of the standard cell library influences can influence any design that uses the standard cell library. Accordingly, the quality of the standard cell library can influence the quality of chips.
With the advent of technology scaling, higher and higher levels of integration became possible due to the shrinking device sizes. At the same time, the technology scaling was providing not only an area scaling but also a delay scaling. According to Moore's “Law”, chips were doubling their speed every 18 months. While this “law” has been applicable for more than 20 years, technology has come to a point where process scaling no longer delivers the expected speed increases. This is mainly due to the fact certain device parameters have reached atomic scales. The trend among devices is that the devices are moving from 0.065 micron to 0.040 micron technologies. A major foundry is projecting similar trends not only for current offerings of 0.040 micron but also for the future 0.032 micron technologies. One of the consequences of this speed saturation due to technology scaling is that designers need to work harder at each stage of the design flow to squeeze out the last remaining circuit performance advantages.
Put another way, even small speed improvements will come at significantly higher design efforts than in the past. Accordingly, it would be desirable to have improved standard cell libraries, as this is one element that greatly influences a wide range of products.